Red River Waterway Commission steps up weevil program to kill salvinia

The Red River Waterway Commission’s new research biologist is on the job. Allie Cozad's mission is to raise armies of giant salvinia eating weevils to release on infested areas of the Red River. She realizes it's an uphill battle.

“It takes a lot of weevil to do a lot of damage," Cozad said by phone, adding that the salvinia problem feels like job security as she starts her work as a commission employee.

The commission started a weevil breeding program almost two years. To date, Cozad said she's released about 45,000 adult weevils into areas of the Red River that are clogged by this Brazilian aquatic weed.

“I’ve seen in some areas where we’ve put the weevils there’s been holes in the salvinia mat where the salvinia has ground up so much and died. Eventually, it loses its buoyancy and sinks to the bottom and that creates a hole in the mat of salvinia," Coazad said.

Red River Waterway Commission operations director Mike Boydstun took an aerial tour last week to assess the salvinia situation along the Red River. He found that the areas north of Natchitoches -- like Coushatta and Shreveport -- aren’t in too bad of shape. The big problem is in Natchitoches, he said, so that’s where the commission is deploying an aggressive application of herbicides by airboats and planes.

"The treatments have done very well; unfortunately, we’re not able to treat 100 percent of the areas where salvinia is invested," Boydstun said.

That’s where Allie Cozad comes in. She plans to infest patches of the Red River with weed-eating weevils where the chemical spray can’t get to. She also aims to breed a cold-tolerant weevil that will stay alive year round.